Copilot Triggers Extension

A lightweight VS Code extension that auto-starts Copilot Chat and renders workspace markdown triggers via the single @copilot-trigger participant.

https://marketplace.visualstudio.com/items?itemName=yash-vs-ext.copilot-triggers

Key Features

Installation

From Marketplace

1. Open the Extensions view (Ctrl/Cmd+Shift+X)
2. Search for "Copilot Triggers"
3. Install
4. Reload (if VS Code doesn't auto‑reload)

Manual / Local (VSIX)

From the extension root folder:

npm install
npm run package   # creates a .vsix via vsce
code --install-extension copilot-triggers-*.vsix

Packaging relies on the onStartupFinished activation event (see VS Code docs) so startup is not delayed.

Packaging & Publishing (Maintainers)

npm run package   # create VSIX
npm run publish   # publish (requires VSCE_PAT environment variable)

Auto-Start Logic

On activation (triggered by onStartupFinished) the extension reads process.env.COPILOT_TASK:

• Empty / unset → Prefills @copilot-trigger help.
• Matches <doc>:<args> (split on the FIRST colon only) → Prefills @copilot-trigger <doc> <args>.

Environment variables are available because VS Code launches the extension host as a Node.js process before this activation event fires (see official Activation Events documentation). No additional configuration is required beyond exporting the variable in the shell / container environment before VS Code starts.

Creating a New Trigger (Workspace Author)

1. Create .copilot-triggers/myflow.md in the workspace root.
2. Add content using placeholders as needed.
3. Optional: Add a one-line description as a blockquote right after the heading (the extension will extract this and display it in help).

Example:

# My Flow

> One-line description of what this trigger does

Target: {{TARGET}}
Args: {{ARGS}} ({{ARGC}} total)

Description Format:

• Must be a blockquote (line starting with >) immediately after the heading
• Blank lines between heading and blockquote are okay
• Will be displayed in @copilot-trigger help output

Usage:

@copilot-trigger myflow foo bar baz

Argument Placeholders

Help Override

If .copilot-triggers/help.md exists it replaces the built-in help. Otherwise the extension renders the internal fallback help document listing available triggers.

Using in Codespaces (Environment Auto-Start)

Set COPILOT_TASK before the Codespace (or local dev container) starts and the first chat will be auto‑seeded:

Options

• Codespaces UI: Repository → Codespaces → Create → Add variable COPILOT_TASK.
• Codespaces Secret (persistent): Settings → Codespaces → Secrets → New secret COPILOT_TASK.
• devcontainer.json: Add under containerEnv (good for defaults):

{
  "containerEnv": { "COPILOT_TASK": "myflow:alpha beta" }
}

• Shell export before launching code . locally.

Accepted Pattern

COPILOT_TASK="<doc>:<raw argument string>"

Only the first colon divides the template name from the rest; additional colons stay inside the argument string. If your arguments contain spaces, just include them—they are passed as a single string then tokenized for placeholders.

Examples

export COPILOT_TASK="help:"
export COPILOT_TASK="myflow:customer-123 refresh"
export COPILOT_TASK="deploy-plan:staging:api v2 rollout"

Behavior Summary

Contributing

• Add new participant logic carefully; keep core extension orchestration-only.
• Avoid network calls: let Copilot Agent + MCP servers handle data fetching.
• Use .copilot-triggers/ for extensibility instead of modifying extension code.

License

MIT